A decrease in meal frequency did not alter body composition, glucose tolerance or glucose utilization in adult dogs fed one or four meals per 48 hours for 246 days. Consumption of a high-fat diet increased body fat gain in adult dogs. (3H)-Ouabain binding to muscle preparations was utilized to estimate the number of Na ion, K ion-ATPase enzyme units in hindlimbs from 8-week old lean and obese mice. The number of enzyme units in obese mice was less than half the number observed in lean mice.